C# Inheritance stackoverflow exception

Acces to list in Form1 without creating a new instance

Fix : passed my listboxes and lists in the constructor of the stack class. Removed inheritance of Form1.

I'm currently working on a calculator with reverse polish notation to learn about stacks, abstract classes, inheritance etc. I get a stackoverflow error when i try to inherit from Form1 in my abstract class.

The question is: Is there a way to prevent this error from happening and get acces to two lists in my Form1? When i use Form1 form1 = new Form1(); I create a new instance of Form1, and the result is an empty list, so i was thinking about inheriting Form1.

I inherit from this class, because I'm trying to reach this two lists in my Form 1:

In the Form1 class i've got 2 lists:

public List<string> lastEventList = new List<string>();
public List<string> stackDisplayList = new List<string>();

This is my abstract class:

using System;
using System.Windows.Forms;

namespace HP_calculator
{
    abstract class Stack : Form1
    {
        ListBox lastEvent, stackDisplay;
        public Stack() { }
        public Stack(ListBox lastEvent, ListBox stackDisplay)
        {
            this.lastEvent = lastEvent;
            this.stackDisplay = stackDisplay;
        }
        public abstract int Pop();
        public virtual void Push(int i)
        {
            //how to acces list
            lastEventList.Add("Pushed " + i + " on stack");
            ((CurrencyManager)lastEvent.BindingContext[lastEventList]).Refresh();
            string addItem = String.Format("[{0}] \t -> \t {1}", 11 - Count(), i);
            stackDisplayList.Add(addItem);
            ((CurrencyManager)stackDisplay.BindingContext[stackDisplayList]).Refresh();
        }
        public abstract int Count();
    }
}

My Form1 class:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace HP_calculator
{
    public partial class Form1 : Form
    {
        Stack stack;
        public List<string> lastEventList = new List<string>();
        public List<string> stackDisplayList = new List<string>();
        public Form1()
        {
            InitializeComponent();
            stackChoice.SelectedIndex = 0;
            lastEvent.DataSource = lastEventList;
            stackDisplay.DataSource = stackDisplayList;
        }

        private void zero_Click(object sender, EventArgs e)
        {
            numberInput.AppendText("0");
        }

        private void one_Click(object sender, EventArgs e)
        {
            numberInput.AppendText("1");
        }

        private void two_Click(object sender, EventArgs e)
        {
            numberInput.AppendText("2");
        }

        private void three_Click(object sender, EventArgs e)
        {
            numberInput.AppendText("3");
        }

        private void four_Click(object sender, EventArgs e)
        {
            numberInput.AppendText("4");
        }

        private void five_Click(object sender, EventArgs e)
        {
            numberInput.AppendText("5");
        }

        private void six_Click(object sender, EventArgs e)
        {
            numberInput.AppendText("6");
        }

        private void seven_Click(object sender, EventArgs e)
        {
            numberInput.AppendText("7");
        }

        private void eight_Click(object sender, EventArgs e)
        {
            numberInput.AppendText("8");
        }

        private void nine_Click(object sender, EventArgs e)
        {
            numberInput.AppendText("9");
        }

        private void clear_Click(object sender, EventArgs e)
        {
            ////////////Make a call to a clear method
            //Clear stack numberinput etc.
            stack = null;
            NewStack();
            numberInput.Clear();
            lastEventList.Add("Stack cleared");
            ((CurrencyManager)lastEvent.BindingContext[lastEventList]).Refresh();
        }
        private void plus_Click(object sender, EventArgs e)
        {
            stack.Push(stack.Pop() + stack.Pop());
        }

        private void minus_Click(object sender, EventArgs e)
        {
            stack.Push(stack.Pop() - stack.Pop());
        }

        private void multiply_Click(object sender, EventArgs e)
        {
            stack.Push(stack.Pop() * stack.Pop());
        }

        private void divide_Click(object sender, EventArgs e)
        {
            //delen door 0 kan niet

            int a = stack.Pop();
            int b = stack.Pop();
            if (a != 0)
            {
                stack.Push(a + b);
            }
            else { MessageBox.Show("Poging om door 0 te delen!", "Invoer error", MessageBoxButtons.OK, MessageBoxIcon.Error); }
        }

        private void enter_Click(object sender, EventArgs e)
        {
            //add to selected stack
            try
            {
                //fix adding in displays after error
                int number = Convert.ToInt32(numberInput.Text);
                stack.Push(number);
                //als het gelukt is, maak dan een call naar deze methode
                //add stack content to stackDisplay 
                //add index
                lastEvent.SelectedIndex = lastEvent.Items.Count - 1; 
                numberInput.Clear();
            }
            catch
            {
                MessageBox.Show("De invoer is ongeldig!", "Invoer error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }

        private void stackChoice_SelectedIndexChanged(object sender, EventArgs e)
        {
            //zorg ervoor dat je ondertussen kunt switchen en de stack dus wordt overgezet
            List<int> temporary = new List<int>();
            if (stack != null)
            {
                while (stack.Count() > 0)
                {
                    temporary.Add(stack.Pop());
                }
            }
            NewStack();
            for(int i = temporary.Count -1; i >= 0; i--){
                stack.Push(temporary.Last());
                temporary.RemoveAt(i);
            }
        }
        private void NewStack()
        {
            if (stackChoice.Text == "My list stack") { stack = new MyListStack(lastEvent,stackDisplay); }
            if (stackChoice.Text == "List stack") { stack = new ListStack(lastEvent, stackDisplay); }
            if (stackChoice.Text == "Array stack") { stack = new ArrayStack(lastEvent, stackDisplay); }
        }
    }
}

An example of another class:

using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace HP_calculator
{
    class ListStack : Stack
    {
        private List<int> stack;
        public ListStack(ListBox lastEvent, ListBox stackDisplay)
            : base(lastEvent, stackDisplay)
        {
            this.stack = new List<int>();
            this.stack.Capacity = 10;
        }
        public override int Pop()
        {
            int result = -1;
            if(stack.Count > 0)
            {
                result = stack.LastOrDefault();
                stack.RemoveAt(stack.Count -1);
            }
            else
            {
                MessageBox.Show("De stack is leeg!", "Error in de stack", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            return result;
        }
        public override void Push(int i)
        {
            if (stack.Count < stack.Capacity)
            {
                stack.Add(i);
                base.Push(i);
            }
            else
            {
                MessageBox.Show("De stack zit vol!", "Error in de stack", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
        public override int Count()
        {
            return stack.Count;
        }
    }
}

Do you know how to prevent the stackoverflow error and get acces to those lists?